mfd: ac100: Add driver for X-Powers AC100 audio codec / RTC combo IC

The AC100 is a multifunction device with an audio codec subsystem and
an RTC subsystem. These two subsystems share a common register space
and host interface.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 2d1fb64..ccf73aab 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -112,6 +112,16 @@
 	help
 	  Support for the BCM590xx PMUs from Broadcom
 
+config MFD_AC100
+	tristate "X-Powers AC100"
+	select MFD_CORE
+	depends on SUNXI_RSB
+	help
+	  If you say Y here you get support for the X-Powers AC100 audio codec
+	  IC.
+	  This driver include only the core APIs. You have to select individual
+	  components like codecs or RTC under the corresponding menus.
+
 config MFD_AXP20X
 	tristate
 	select MFD_CORE